Product Description

The AR102 4" f/6.5 Apochromatic Refractor Telescope from Explore Scientific is a powerful optical tube assembly that can be used to see detailed views of celestial objects from the Moon to bright deep sky objects. It is also portable enough to be used as a grab-and-go option over larger and heavier scopes, or it can be easily removed from the included mount and set up on a dual-mount rig for astrophotography/astroimaging. Its fully multicoated achromatic doublet lens configuration correct for spherical and chromatic aberrations to create images that are clear and bright without distortion across the entire field of view, with true color rendition.

The AR102 is equipped with 2" Crayford-style focuser, instead of the more common 1.25" focusers typically used. Unlike a traditional rack-and-pinion focuser, a Crayford-style uses a steel rod held tightly against the focus tube. This toothless friction system eliminates backlash and enables ultra-fine precision focusing. A large coarse-focus wheel quickly brings subjects into rough focus and then the 10:1 fine-focus allows the user to precisely focus it without the risk of losing it as soon as the knob is released. The large eyepiece holder provides an expansive amount of angular view required for wide-field observations for long periods.

This scope features a mounting cradle-ring that clamps over the OTA and lets the user adjust the orientation and position of the scope relative to the mount to optimize viewing comfort and balancing, while avoiding interference with other equipment. Integrated into the cradle-ring is a carrying handle for easier transportation and set-up. The OTA attaches to the Twilight I Alt-Azimuth mount using Vixen-style dovetail plate, so it can easily be swapped with other compatible mounts, and other OTAs will similarly fit onto the mount. Users control the mount using two flexible control arms with large knurled knobs for a sure grip. A chrome-plated 3-section steel tripod provides a solid platform for observations. Also included with the scope are a 90° erect-image diagonal for more comfortable viewing, and an 8x50 finderscope with a quick-release bracket.

Optical Performance

4" 102mm objective lens

663mm focal length

Focal ratio: f/6.5

Refractor-style optical design

Anti-reflection fully multicoatings on all optics

Doublet optical design reduces spherical and chromatic aberrations

2" Crayford Focuser

Accepts 2" eyepieces and accessories

Crayford-style two-speed focuser

Two coarse focus wheels, one on each side of eyepiece holder

Fine smaller focus dial on right-side of eyepiece holder

Crayford focusers use a toothless friction system that allows for super-fine precision focusing without backlash

Twilight I Alt-Azimuth Mount and Tripod

Mount

Worm-gears on Alt and Azimuth axes

Slow-motion control cables

Head can be tilted back-to-front to a 45° angle

Can also be set to point straight up for viewing at the zenith

Powder-coated aluminum

Wrench for adjusting the mount is stored in the fork arm, and held in place with a magnet

Tripod

Footprint: 42"

Payload capacity: 15 lb

3-sectio chrome-plated steel legs

Designed to hold a small to medium sized refractor, or a lightweight reflector